Bottled liquid dispensers

ABSTRACT

Bottled water or other liquid is supplied via a bottle connector  5  for releasable sealing engagement with a neck formed on the bottle, and a transfer tube  6  to a reservoir  7  wherein the water may be cooled. The bottle connector  5,  the transfer tube  6  and the reservoir  7  are all moulded of a plastics material containing silver bound in a ceramic ion exchange resin so that the silver ions (Ag+) are slowly released to prevent microbial growth on the surface of the components. The bottle connector may include a feed tube  21  or a dip tube which also releases silver ions. Furthermore, the transfer tube  6  may be connected to the reservoir  7  via a reservoir connector  29  which may incorporate a draw tube  31  and one or more outlet tubes  14, 36,  e.g. leading to a discharge outlet, all of which release silver ions.

TECHNICAL FIELD OF THE INVENTION

This invention relates to bottled liquid dispensers of the kind in whicha liquid (usually water) is supplied from a bottle to a discharge outletvia a reservoir. Generally (but not always) the liquid is heated orcooled in the reservoir.

BACKGROUND

Over the years a great deal of attention has been paid to improving thehygiene in bottled liquid dispensers, more particularly to prevent themultiplication of any bacteria which could cause health problems.

In the past the reservoir and its associated components were fixed inthe dispenser and it was necessary to sanitize them in situ duringperiodic routine maintenance.

FR 2 685 293 A1 proposes to separate the liquid from any air whichenters the bottle by sealing the liquid within a separate collapsablebag. However, a more common approach to reducing the risk ofcontamination with air-bourne pathogens is to filter the air before itenters the bottle.

Another sanitizing measure proposed in GB 1 552 559 is to place a porousceramic body between the bottle and the reservoir. The ceramic bodycontains metallic silver which it is claimed will disinfect the water asit flows into the reservoir. However, it is doubtful whether such briefcontact would achieve effective and lasting sanitization.

The most effective solution to date which is the subject of EP 0 581 491A (Ebac Limited) is to provide a disposable reservoir in combinationwith a feed tube unit which is releasably supported beneath the bottlefor connection therewith so that the feed tube unit, reservoir andinterconnecting pipework (known as a Watertrail* assembly) can beperiodically removed and replaced with clean components. Although thissystem is very reliable at minimising the risk of bacterial growth ifthe Watertrail* assembly is changed at the recommended intervals thereis a constant desire to improve the level of hygiene.

The present invention seeks to provide a new and inventive form ofliquid dispensing apparatus which provides an even greater increase inhygiene compared with existing apparatus.

SUMMARY OF THE INVENTION

The present invention proposes a bottled liquid dispenser in whichliquid is supplied from a bottle to a discharge outlet via a reservoir,wherein the dispenser includes a bottle connector for releasable sealingengagement with a neck formed on the bottle and conduit means forconducting liquid from the bottle connector to the reservoir, in whichat least the bottle connector, the conduit means and the reservoir areformed of or lined with a material containing silver in a bound formwhich releases silver ions (Ag+) into the liquid from the surface of thematerial at a controlled rate.

Silver ions have a known antimicrobial action which is effective againstmost bacteria, yeasts, fungi and similar microbes. They bindnon-specifically to the cell membrane and disrupt normal membranefunction. They also pass through cell wall by a variety of mechanismsincluding active transport systems which normally move essential ionsinto the cell. Once inside the cell they readily combine with electrondonor groups containing sulphur, oxygen and nitrogen as well asnegatively charged groups such as phosphates and chlorides. Silver ionsalso combine with thiol (—SH) groups commonly found in enzymes, causingthem to become denatured due to critical conformational changes in theenzyme molecule. As a result, normal cellular processes are disruptedand the cell quickly becomes poisoned and dies.

By distributing the release of silver ions material over the internalsurfaces of the main components which come into direct contact with theliquid any microbes are attacked at the solid-liquid interface wherethey are most likely to lodge and multiply. On the other hand, thelevels which are released are insufficient to cause a risk to the healthof higher animals since the ions are greatly diluted when they enter thebody of the liquid, and they are also inactivated by non-specificbinding with proteins, salts and other substances long before they enterthe animal body.

The material which releases silver ions is preferably an ion exchangeresin which slowly releases silver ions to be replaced by monovalentcations from the liquid. Most liquids will contain such cations in theform of sodium (Na+), potassium (K+), hydrogen (H+) etc.

A preferred form of ion exchange resin is a zirconium phosphate-basedceramic which, among other attributes, has high temperature stabilityand low colour formation. The resin may thus conveniently be added toplastic moulding materials (masterbatch) in a particulate form prior tomoulding of the components, generally in a proportion of no more than 2%by weight.

The conduit means is preferably a transfer tube which connects thebottle connector to a separate reservoir.

The reservoir may be provided with thermal means for controlling thetemperature of liquid in the reservoir, either by heating or cooling theliquid.

The bottle connector may take various forms and may incorporate a feedtube arranged to project into the neck of the bottle which is supportedwith the neck downwards or a dip tube which projects down into a bottlewhich is supported with its neck upwards. Such a feed tube or dip tubeare preferably formed of or coated with the material which releasessilver ions.

The apparatus may further include at least one outlet tube forconducting liquid from the reservoir to the discharge outlet, in whichcase the or each outlet tube is preferably formed of or lined with thematerial which releases silver ions.

The transfer tube and the or each outlet tube is preferably connectedwith the reservoir via a reservoir connector, and this too is preferablyformed of or lined with the material which releases silver ions. Thereservoir connector may incorporate a draw tube which projects into thereservoir for removing liquid therefrom, in which case the draw tube ispreferably formed of or coated with the material which releases silverions.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description and the accompanying drawings referred totherein are included by way of non-limiting example in order toillustrate how the invention may be put into practice. In the drawings:

FIG. 1 is a schematic drawing showing the main components of a watercooler in accordance with the invention; and

FIG. 2 is a general view of various components which are incorporated inthe water cooler.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIG. 1, the illustrated water cooler includes a housing 1which is provided with a seat 2 for receiving a water bottle 3 which ismounted in an inverted position with its neck 4 inserted through anaperture in the seat 2. The neck is sealably engaged with a bottleconnector 5 which is removably mounted within the housing 1, and fromwhich a transfer tube 6 conducts water from the bottle to a reservoir 7,also removably mounted within the housing. Water displaced from thebottle is replaced by air which enters the bottle connector 5 via amicrofilter 8 and a non-return valve 9. Water contained within thereservoir 7 may be cooled by a refrigeration system which includes acompressor 11, an air-cooled condenser 12 and an evaporator 13 which ismounted in close thermal contact with the reservoir 7. Chilled water isremoved from the reservoir 7 via an outlet tube 14 which terminates in adischarge outlet 15 disposed above a dispensing recess 16 formed in thehousing 1, flow control being achieved by means of a pinch valve 18which may be as disclosed in patent specification No. EP 0 581 492 (EbacLimited).

It will be appreciated that although the water is normally cooled in thereservoir 7, an outlet could be provided for dispensing water at ambienttemperature. Furthermore, water could be supplied to a hot tank to beheated an dispensed above ambient temperature, for use in hot beveragesfor example.

The bottle connector 5, reservoir 7 and tubes 6 and 14 are included in areplaceable Watertrail* assembly which is broadly as described in EP 0581 491 A (Ebac Limited), and which is shown in more detail in FIG. 2.The connector 5 includes a cup-like manifold body 20, moulded of ABS,which incorporates a feed tube 21 which projects upwardly into the neckof the bottle. The manifold body also incorporates additional componentssuch as the air filter 8 and a one way valve 9, which includes the cap22, valve seat member 23, silicone valve disc 24 and float 25. Any waterleakages are conducted to waste by a drain tube 26. The transfer tube 6,which is moulded of LDPE, connects with a spigot 27 on the bottleconnector 5 to conduct water from the feed tube 21 to an inlet spigot 28formed on a reservoir cap 29 moulded of HDPE. The cap engages with acylindrical collar 30 formed on the reservoir 7, formed of blown HDPE,which may be received in a heat-insulated receptacle (not shown)incorporating the evaporator 13 (not shown). The cap 29 includes a drawtube unit 31, also of HDPE, through which chilled water can be removedfrom the lower part of the reservoir 7. The outlet tube 14 is formed ofsilicone rubber and engages a reservoir outlet spigot 33 formed on thecap 29. A further outlet spigot 34 may be provided on the cap 29 inknown manner to conduct water to a hot tank and/or ambient water outlet(not shown) via an ambient outlet tube 36, also of silicone rubber.

In accordance with the invention, the manifold body 20, transfer tube 6,the reservoir cap 29, draw tube unit 31, reservoir 7 and outlet tubes 14and 36 all incorporate an antimicrobial agent in the form of aparticulate zirconium phosphate based ceramic ion exchange resincontaining bound silver. A suitable additive is commercially availablefrom Milliken Chemical under the trade name AlphaSan RC 5000. The agentis mixed with the moulding composition in a proportion of up to 2% byweight prior to moulding of the components. When the Watertrail*assembly is in use the resin releases silver ions into the interfacebetween the plastics substratum and the water contained in the assemblyat a steady controlled rate. As a result, tests show that theWatertrail* assembly of the invention is capable of inhibiting bacterialgrowth within the treated components for a considerable time, well inexcess of the normal period recommended for replacement of theWatertrail* assembly. Although the antimicrobial agent only acts at thecomponent-water interface it will be appreciated that since surfacemultiplication of bacterial, fungi and yeasts is prevented the wholesystem is effectively sanitized as long as the ion exchange resinremains active. In normal use of the dispenser and microbes present inthe main volume of liquid are carried through the apparatus before theymultiply to a significant level.

Clearly the components which do not come into contact with water whichmay be ingested need not be treated with the antimicrobial agent.Therefore, the components of the valve assembly 9 and the drain tube 26can be of normal untreated plastics. It will further be apparent thatsince only the surfaces of the components which come into contact withthe water need be treated it would be possible to coat such surfaces ofthe relevant components with a material containing the ion exchangeresin.

It should also be noted that although the general form of water coolerdescribed herein is widely used the invention is not limited to suchwater coolers. For example, the bottle could be mounted with its neckuppermost, in which case the bottle connector would incorporate a diptube for removing water from the lower part of the bottle. Water may bedisplaced by pressurising the air space within the bottle, as describedin EP 1 118 582 A2 of Ebac Limited for example.

It will be appreciated that the features disclosed herein may be presentin any feasible combination. Whilst the above description lays emphasison those areas which, in combination, are believed to be new, protectionis claimed for any inventive combination of the features disclosedherein.*Watertrail is a registered trade mark of Ebac Limited.

1. A bottled liquid dispenser in which liquid is supplied from a bottleto a discharge outlet via a reservoir, wherein the dispenser includes abottle connector for releasable sealing engagement with a neck formed onthe bottle and conduit means for conducting liquid from the bottleconnector to the reservoir, characterised in that at least the bottleconnector, the conduit means and the reservoir are formed of or linedwith a material containing silver in a bound form which releases silverions (Ag+) into the liquid from the surface of the material at acontrolled rate.
 2. A bottled liquid dispenser according to claim 1, inwhich the material which releases the silver ions includes an ionexchange resin.
 3. A bottled liquid dispenser according to claim 2, inwhich the ion exchange resin is a ceramic.
 4. A bottled liquid dispenseraccording to claim 3, in which the ion exchange resin is a zirconiumphosphate based ceramic.
 5. A bottled liquid dispenser according toclaim 2, in which particles of the ion exchange resin are dispersed in amoulded plastics substrate.
 6. A bottled liquid dispenser according toclaim 5, in which the proportion of ion exchange resin in the plasticssubstrate is less than 2% by weight.
 7. A bottled liquid dispenseraccording to claim 1, in which the bottle connector incorporates a feedtube or a dip tube which is arranged to project into the neck of thebottle and which is formed of or coated with the material which releasessilver ions.
 8. A bottled liquid dispenser according to claim 1,including at least one outlet tube for conducting liquid from thereservoir to the discharge outlet and the or each outlet tube is formedof or lined with the material which releases silver ions.
 9. A bottledliquid dispenser according to claim 8, in which the conduit means andthe or each outlet tube is connected with the reservoir via a reservoirconnector which is formed of or lined with the material which releasessilver ions.
 10. A bottled liquid dispenser according to claim 9, inwhich the reservoir connector incorporates a draw tube which projectsinto the reservoir for removing liquid therefrom and the draw tube isformed of or coated with the material which releases silver ions.